The next time you wake up in the morning with an itch in your nose, it might not be a case of hay fever.
A six-legged creature might have found its way into your nostril while you were asleep.
Fortunately, for those with a phobia of insects, such cases are not common in Singapore, said Dr Kenny Pang, an ear, nose, throat (ENT) specialist at Asia Sleep Centre with more than 20 years of experience.
However, that does not mean that they are merely the stuff of nightmares.
Ants, spiders and cockroaches are some of the pests that can crawl into our bodies through our ears and nostrils, added Dr Pang.
In 2014, ABC News reported that Australian doctors had pulled out a 2cm cockroach from a man's right ear after it crawled in while he was asleep and caused a sharp pain.
Avoid doing this
Think an insect has crawled into your head through your nose or ear? If so, seek medical attention immediately. Here are some things to avoid doing:
1 Pouring in a liquid or oil
Trying to drown the insect risks agitating it and causing it to turn violent, possibly resulting in trauma to the organ. Also, there is no guarantee that this will work as some bugs, like roaches, can live without air for more than 30 minutes.
2 Using a sharp instrument
Probing your nostril or ear with a sharp instrument like a pair of tweezers might cause injury to the skin lining. In severe cases, bones in the middle ear might be damaged, requiring further treatment.
3 Blowing hard into the ear or nose
This is not advisable as the insect might burrow deeper to escape. Its movements might tear the ear drum, potentially resulting in hearing loss.
4 Spraying insecticide
Insecticides contain powerful poisons that can cause muscle paralysis if the chemicals are inhaled or absorbed by the mucous membrane of the nose.
If the environment is dirty, there will be more creepy-crawlies. And if we smell like rotting food, cockroaches will be attracted to us.
DR LYNNE LIM, an ENT specialist with a practice at Mount Elizabeth Medical Centre, on the importance of maintaining personal hygience.
Earlier this month, a woman in Chennai, India, underwent surgery to remove a roach that had been lodged in her skull for 12 hours.
It had squirmed up her nostril and caused "a burning sensation" whenever it moved, according to The New Indian Express.
On Feb 7, The Star reported that a man in Chengdu, China, ended up in hospital to have the carcass of a 1cm roach extracted from his ear.
He had killed it with pesticide, after failing to remove it with toothpicks and a pair of tweezers.
But while the pesticide killed the bug eventually, doctors here do not recommend taking matters into your own hands.
When an insect has crawled into your nostril or ear, "avoid trying to use instruments to remove it", said Dr Pang.
Doing so could backfire and cause trauma to the skin lining in the nose canal or cause perforations in the ear drums.
Moreover, as some bugs like cockroaches cannot move backwards, trying to pry them out could cause them to burrow further in.
Such cases are rare in Singapore. But Dr Lynne Lim, an ENT specialist with a practice at Mount Elizabeth Medical Centre, has encountered two of them.
The first case in 2012 involved a homeless, elderly man who had "more than 30 maggots" in his nose and sinuses after sleeping outdoors for months.
Despite having a "blocked, bleeding and ulcerated" nose, he sought medical attention only after a live maggot crawled out of his nostril.
The second case was in 2013, when a cockroach crawled into a labourer's ear while he was asleep, causing severe pain as it burrowed its way in. Dr Lim had to remove its legs and wings before extracting it.
The more common symptoms of such incidents include pain, discharge and bleeding in the nostril or ear. It is also possible that the patient may hear the bug struggling to get out of the body.
The insect's movements can cause extreme pain in the head as the ears and nose are highly sensitive organs.
If the bug is left alone, there is a risk of it dying inside the body and the carcass may cause infections.
Dr Lim said some flesh-eating maggots can work their way through tissues to other body parts. If left in the body for an extended period, the maggots might lay eggs and breed.
Removing the bug depends on how deep inside it is. If it is in the outer ear canal, one way is to tilt the head and let gravity draw it out.
Otherwise, consult an ENT specialist if the bug has burrowed deeper into the canal, as general practitioners do not have fine instruments like forceps or suction machines to remove the insect.
However, doctors urge prevention over cure. One way is to maintain personal hygiene.
Dr Lim said: "If the environment is dirty, there will be more creepy-crawlies. And if we smell like rotting food, cockroaches will be attracted to us."
Dr Kevin Soh of Mount Elizabeth Hospital cautioned against trimming the hairs in the nostril and ear canals too finely, as they act as barriers to prevent bugs from entering.
Some bodily mechanisms are designed to deter insects from entering the head. This includes cerumen - also known as ear wax - that can trap the bugs.
Dr Soh added: "Many people find ear wax disgusting, but so do bugs."
Otherwise, sleeping with earplugs can save you a trip to the ENT doctor the next morning.